Backlight unit and display device

Abstract

The invention provides a backlight unit and a display device. The backlight unit (100) comprises a substrate (10), a first reflecting layer (11), a second reflecting layer (12) and a light emitting unit (14). The first surface (S1) of the substrate (10) is provided with a groove (G); the first reflecting layer (11) covers part of the inner wall of the groove (G). The second reflective layer (12) covers the first surface (S1). The second reflecting layer (12) is provided with an opening (H), the orthographic projection of the opening (H) on the substrate (10) falls into the orthographic projection of the groove (G) on the substrate (10), and the second reflecting layer (12) is not in contact with the inner wall of the groove (G). The light-emitting unit (14) is arranged on the side, away from the substrate (10), of the second reflecting layer (12). Wherein the second reflecting layer (12) comprises a first pattern layer (121) and a second pattern layer (122) which are laminated, the first pattern layer (121) comprises a first hollow (K1) corresponding to the groove (G), and the second pattern layer (122) comprises a reinforcing pattern (P) arranged around the first hollow (K1).

Description

Backlight unit and display device TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, and in particular, to a backlight unit and a display device. BACKGROUND

[0002] Passive light-emitting display devices mainly include a display panel and a backlight module, wherein the display panel is located on the light-out side of the backlight module, and the display panel is used for modulating the light emitted by the backlight module, so as to realize image display. Due to the development trend of thin display devices, the thinning of the backlight module is a research hotspot in the industry.

[0003] SUMMARY

[0004] The present disclosure provides a backlight unit and a display device to reduce the thickness of the backlight unit and improve stability.

[0005] In a first aspect, the present disclosure provides a backlight unit, comprising:

[0006] a substrate, a first surface of the substrate being provided with a groove;

[0007] a first reflective layer covering part of the inner wall of the groove;

[0008] a second reflective layer covering the first surface; the second reflective layer comprises an opening, a normal projection of the opening on the first surface is located within a normal projection of the corresponding groove on the first surface, and the second reflective layer does not contact the inner wall of the groove;

[0009] a light-emitting unit located on a side of the second reflective layer away from the substrate;

[0010] The second reflective layer comprises a first pattern layer and a second pattern layer arranged in a stack; the first pattern layer comprises a first hollow, a normal projection of the first hollow on the first surface coincides with a normal projection of the opening on the first surface; the second pattern layer comprises a reinforcing pattern; the reinforcing pattern is arranged around the first hollow, and a normal projection of the reinforcing pattern on the first surface at least partially falls within a normal projection of the corresponding groove on the first surface.

[0011] In some backlight units provided by the present disclosure, the second pattern layer is located on a side of the first pattern layer away from the substrate.

[0012] In some backlight units provided by the present disclosure, the normal projection of the reinforcing pattern on the first surface is a central symmetric pattern.

[0013] In some backlight units provided by the present disclosure, the center of symmetry of the normal projection of the reinforcing pattern on the first surface coincides with the geometric center of the normal projection of the groove on the first surface.

[0014] In some backlight units provided by the present disclosure, the reinforcing pattern comprises a plurality of strip structures, and / or a plurality of ring structures.

[0015] In some backlight units provided by the present disclosure, the extension directions of all the strip structures of the same reinforcing pattern intersect at a first point; the first point is located within the opening.

[0016] In some backlight units provided by the present disclosure, the first point and the geometric center of the groove are located on the same straight line perpendicular to the first surface.

[0017] In some backlight units provided by the present disclosure, the number of strip structures included in the reinforcing pattern is greater than or equal to 8.

[0018] In some backlight units provided by the present disclosure, the dimension of the strip structure perpendicular to the extension direction thereof is greater than or equal to 3 μm;

[0019] The dimension B1 of the strip structure perpendicular to the extension direction thereof is not greater than 100 μm.

[0020] Wherein, L represents the circumference of the orthographic projection of the first hollow on the first surface, n represents the number of strip structures included in the same reinforcing pattern, C1 represents the distance between the end portions of two adjacent strip structures on the side close to the first hollow, and the value of C1 is greater than or equal to 10 μm.

[0021] In some backlight units provided by the present disclosure, any two ring structures of the plurality of ring structures are coaxial and arranged at the same angle, and the orthographic projections of each of the two ring structures on the first surface are similar figures.

[0022] In some backlight units provided by the present disclosure, the orthographic projection of the ring structure on the first surface is a circular ring.

[0023] The radial width of the ring structure is between 3 μm and 100 μm.

[0024] The distance between two adjacent ring structures in the radial direction is between 10 μm and 100 μm.

[0025] In some backlight units provided by the present disclosure, the strip structures and the ring structures intersect with each other to form a grid structure.

[0026] In some backlight units provided by the present disclosure, the reinforcing pattern comprises a plurality of second hollows.

[0027] In some backlight units provided by the present disclosure, the maximum dimension of the second hollow is between 3 μm and 100 μm.

[0028] The distance between two adjacent second hollows is between 10 μm and 100 μm.

[0029] In some backlight units provided by the present disclosure, the first surface has a first contour in a projection on the first surface, and the reinforcing pattern has an inner contour and an outer contour in a projection on the first surface, the first contour being between the inner contour and the outer contour.

[0030] The distance between the outer contour and the first contour is greater than or equal to 50 μm.

[0031] The distance between the inner contour and the first contour is less than or equal to 60 μm.

[0032] In some backlight units provided by the present disclosure, the reinforcing pattern corresponding to different first hollows is directly connected to form an integrated structure.

[0033] In some backlight units provided by the present disclosure, the second pattern layer and the first pattern layer are made of the same material.

[0034] In the two film layers of the second pattern layer and the first pattern layer, the thickness of the film layer close to the substrate side is greater than or equal to the thickness of the film layer away from the substrate side.

[0035] In some backlight units provided by the present disclosure, the first pattern layer has a projection on the substrate covering a projection of the second pattern layer on the substrate.

[0036] The first pattern layer in the area outside the first hollow is a continuous whole layer structure.

[0037] In some backlight units provided by the present disclosure, a protruding structure is further arranged in the groove, the protruding structure is lower than the first surface or flush with the first surface, and the first reflective layer covers the surface of the protruding structure.

[0038] In a second aspect of the present disclosure, a display device is provided, which comprises the backlight unit of any one of the above and a display panel, the display panel being arranged on the side of the substrate of the backlight unit away from the light-emitting unit.

[0039] In a third aspect of the present disclosure, a manufacturing method of a backlight unit is provided, which comprises:

[0040] A mask layer is manufactured on the first surface of the substrate, the mask layer has an etching opening exposing the substrate, and the mask layer comprises a first pattern layer and a second pattern layer arranged in a stack, the second pattern layer comprises a reinforcing pattern, and the reinforcing pattern is arranged around the etching opening.

[0041] The substrate is etched through the etching opening to form a groove, the mask layer corresponds to form a second reflective layer, the etching opening corresponds to form an opening of the second reflective layer, and the projection of the opening on the first surface falls within the projection of the groove on the first surface.

[0042] The second reflective layer is used as a mask to deposit a first reflective layer in the groove.

[0043] The light-emitting unit is arranged on a side of the second reflecting layer away from the substrate.

[0044] In some methods provided by the present disclosure, a mask layer is made on a first surface of a substrate, specifically including:

[0045] A first pattern layer is made on the first surface of the substrate.

[0046] A second pattern layer is made on a side of the first pattern layer away from the substrate.

[0047] The present disclosure has the following advantages:

[0048] The present disclosure provides a backlight unit and a display device. The backlight unit includes a substrate, a first reflecting layer, a second reflecting layer, and a light-emitting unit. The first surface of the substrate is provided with a groove. The first reflecting layer covers part of the inner wall of the groove. The second reflecting layer covers the first surface. The second reflecting layer includes an opening, and the orthographic projection of the opening on the first surface falls within the orthographic projection of the corresponding groove on the first surface. The second reflecting layer does not contact the inner wall of the groove. The light-emitting unit is arranged on a side of the second reflecting layer away from the substrate. The second reflecting layer includes a first pattern layer and a second pattern layer arranged in a stack. The first pattern layer includes a first hollow, and the orthographic projection of the first hollow on the first surface coincides with the orthographic projection of the opening on the first surface. The second pattern layer includes a reinforcing pattern. The reinforcing pattern is arranged around the first hollow, and the orthographic projection of the reinforcing pattern on the first surface at least partially falls within the orthographic projection of the corresponding groove on the first surface. The structure provided by the present disclosure is beneficial to reducing the thickness of the backlight unit, and thus beneficial to reducing the thickness of the display device. In the backlight unit provided by the present embodiment, the second reflecting layer is made into a two-layer structure including the first pattern layer and the second pattern layer. The second pattern layer is provided with the reinforcing pattern around the periphery of the first hollow. The reinforcing pattern strengthens the strength of the roof structure while avoiding the roof structure from falling due to excessive weight, thereby improving the stability of the roof structure. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required to be used in the embodiments of the present disclosure will be briefly introduced below. Obviously, the drawings introduced below are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor.

[0050] FIG. 1 is a schematic diagram of the cross-sectional structure of a backlight module in the related art;

[0051] FIG. 2A is a schematic diagram of the cross-sectional structure of a backlight unit provided by an embodiment of the present disclosure;

[0052] FIG. 2B is a schematic diagram of the cross-sectional structure of another backlight unit provided by an embodiment of the present disclosure;

[0053] FIG. 3 is a schematic diagram of a planar structure of a second reflective layer according to an embodiment of the present disclosure;

[0054] FIG. 4A is a schematic diagram of a cross-sectional structure of a second reflective layer according to an embodiment of the present disclosure;

[0055] FIG. 4B is a schematic diagram of a cross-sectional structure of another second reflective layer according to an embodiment of the present disclosure;

[0056] FIG. 5A is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure;

[0057] FIG. 5B is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure;

[0058] FIG. 6 is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure;

[0059] FIG. 7A is a planar photograph of a second reflective layer for testing according to an embodiment of the present disclosure;

[0060] FIG. 7B is a schematic diagram of a groove etching process according to an embodiment of the present disclosure;

[0061] FIG. 8A is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure;

[0062] FIG. 8B is a schematic diagram of possible shapes of a reinforcing pattern according to an embodiment of the present disclosure;

[0063] FIG. 9 is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure;

[0064] FIG. 10A is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure;

[0065] FIG. 10B is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure;

[0066] FIG. 11A is a schematic diagram of a cross-sectional structure of another backlight unit according to an embodiment of the present disclosure;

[0067] FIG. 11B is a schematic diagram of a cross-sectional structure of another backlight unit according to an embodiment of the present disclosure;

[0068] FIG. 11C is a schematic diagram of a cross-sectional structure of another backlight unit according to an embodiment of the present disclosure;

[0069] FIG. 12 is a schematic diagram of a cross-sectional structure of a display device according to an embodiment of the present disclosure;

[0070] FIG. 13 is a schematic diagram of a cross-sectional structure of another display device according to an embodiment of the present disclosure;

[0071] FIG. 14 is a flowchart of a manufacturing method of a backlight unit according to an embodiment of the present disclosure;

[0072] FIG. 15A is a schematic view of a manufacturing process of a backlight unit according to an embodiment of the present disclosure;

[0073] FIG. 15B is a schematic view of a planar structure of a mask layer according to an embodiment of the present disclosure;

[0074] FIG. 16 is a schematic view of another manufacturing process of a backlight unit according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0075] In order to make the above objectives, features and advantages of the present disclosure more obvious and easy to understand, the present disclosure will be further described below with reference to the drawings and embodiments. However, the example embodiments can be implemented in various forms, and should not be understood as being limited to the embodiments set forth herein; on the contrary, these embodiments are provided to make the present disclosure more comprehensive and complete, and to fully convey the ideas of the example embodiments to those skilled in the art. The same reference signs in the drawings represent the same or similar structures, and thus repeated descriptions thereof will be omitted. The expressions of position and direction described in the present disclosure are described with reference to the drawings, but changes can be made as needed, and the changes made are included in the scope of protection of the present disclosure. The drawings of the present disclosure are only used to illustrate the relative positional relationship and do not represent the true proportions.

[0076] FIG. 1 is a schematic view of a cross-sectional structure of a backlight module in the related art.

[0077] For example, FIG. 1 shows a cross-sectional structure of a typical backlight module in the related art. As shown in FIG. 1, the backlight module in the related art generally includes a lamp plate 1, a color conversion film 2 and a diffusion film 3 and the like film structures located on the light exit side of the lamp plate 1. Since the lamp plate 1, the color conversion film 2 and the diffusion film 3 and the like films are mutually independent film structures, they need to be assembled in a certain way, for example, by means of an adhesive layer to be attached. Thus, it is difficult to further reduce the thickness of the backlight module based on this structure, and it is difficult to meet the development trend of thin display devices.

[0078] In view of this, the first aspect of the present disclosure provides a backlight unit, which is advantageous to overcome the above problems.

[0079] FIG. 2A is a schematic view of a cross-sectional structure of a backlight unit according to an embodiment of the present disclosure; and FIG. 2B is a schematic view of another cross-sectional structure of a backlight unit according to an embodiment of the present disclosure.

[0080] In the embodiments of the present disclosure, as shown in FIGS. 2A and 2B, the backlight unit includes a substrate 10, a first reflective layer 11, a second reflective layer 12 and a light emitting unit 14.

[0081] The substrate 10 is used to carry other structures arranged thereon. The shape and size of the substrate 10 are adapted to the shape and size of the display device to which the substrate 10 is applied. Generally, the shape of the substrate 10 can be square, rectangular, etc. When applied to a display device of a special shape, the shape of the substrate 10 can also be a special shape such as a circle, etc. without limitation. The substrate 10 can be made of a transparent substrate material commonly used in the display technology field, such as optical glass and optical plastic, etc. without limitation.

[0082] The first surface S1 of the substrate 10 is provided with a groove G. Part of the inner wall of the groove G is covered with a first reflection layer. The first reflection layer 11 is used to reflect light to the periphery of the groove G, so as to disperse the light. Specifically, as shown in FIGS. 2A and 2B, the first reflection layer 11 can be arranged at the bottom of the groove G, so that the light reflected by the first reflection layer 11 to the periphery of the groove G is more uniform, without limitation.

[0083] In some embodiments, the orthographic projection of the opening H of the second reflection layer 12 on the first surface S1 completely coincides with the orthographic projection of the first reflection layer 11 on the first surface S1, or the orthographic projection of the opening H of the second reflection layer 12 on the first surface S1 falls within the orthographic projection of the first reflection layer 11 on the first surface S1, so as to ensure that the first reflection layer 11 has sufficient reflection area, and further improve the effect of dispersing light.

[0084] In some embodiments, as shown in FIGS. 2A and 2B, the backlight unit further comprises a protruding structure 101 in the groove. The first reflection layer 11 covers the surface of the protruding structure 101, so as to improve the effect of dispersing light. For example, the bottom of the groove G can be directly upwardly protruding to form the protruding structure 101. In specific implementation, the protruding structure 101 can be formed in various ways. For example, in some embodiments, the protruding structure 101 can be formed at the same time when the groove G is etched on the substrate 10, without limitation.

[0085] In some embodiments, the top of the protruding structure 101 can be lower than the first surface S1, or flush with the first surface S1, without limitation.

[0086] In specific implementation, the bottom of the groove G can also be a relatively flat structure, or a recessed structure, or a concave-convex structure, or other structures, without limitation.

[0087] The second reflection layer 12 covers the first surface S1 of the substrate 10. The second reflection layer 12 comprises an opening H. As shown in FIGS. 2A and 2B, the position of the opening H corresponds to the position of the groove G. The opening H is used to transmit the light emitted by the light emitting unit 14, so as to make the light incident into the groove G.

[0088] In the embodiment, one opening H corresponds to one groove G, and the second reflective layer 12 can be used as a mask when etching the substrate 10, and the substrate exposed by the opening H is etched to form the groove G.

[0089] As shown in FIG. 2A and FIG. 2B, the orthographic projection of the opening H on the first surface S1 falls within the orthographic projection of the corresponding groove G on the first surface S1, and the second reflective layer 12 does not contact the inner wall of the groove G. Specifically, the orthographic projection of the groove G on the first surface S1 has a first contour F1, the orthographic projection of the opening H on the first surface S1 has a second contour F2, and the second reflective layer 12 between the first contour F1 and the second contour F2 protrudes inwardly of the groove G relative to the first contour F1, and the portion of the second reflective layer 12 protruding inwardly of the groove G relative to the first contour F1 does not contact the inner wall of the groove G. The portion of the second reflective layer 12 protruding inwardly of the groove G relative to the first contour F1 has a certain width, and the portion of the second reflective layer 12 relative to the groove G forms a roof structure, which can be used to reflect light and improve the utilization of light. This is not limited herein. In the embodiment, the roof structure is formed by over-etching the substrate 10 located around the opening H and directly below the second reflective layer 12 when etching the substrate 10 using the second reflective layer 12 as a mask.

[0090] In some embodiments, the orthographic projection of the top of the protruding structure 101 on the first surface S1 falls within the orthographic projection of the opening H on the first surface S1, so that the first reflective layer 11 covering the surface of the protruding structure 101 can be fully utilized to reflect the light incident through the opening H to the periphery of the protruding structure 101, thereby improving the uniformity of the reflected light. The top of the protruding structure 101 specifically refers to the portion of the protruding structure 101 away from the second surface S2 of the substrate 10, wherein the second surface S2 is the surface of the substrate 10 opposite to the first surface S1. In the embodiment, the area of the cross section of the protruding structure 101 in the direction parallel to the first surface S1 gradually decreases in the direction from the second surface S2 to the first surface S1, for example, the protruding structure 101 can be formed as a conical structure, so that the first reflective layer 11 attached to the sidewall of the protruding structure 101 forms an inclined plane or an inclined curved surface relative to the first surface S1, which is beneficial to improve the reflection effect of the first reflective layer 11 and further improve the utilization of light. This is not limited herein.

[0091] The orthographic projection of the opening H of the second reflective layer 12 on the first surface S1 completely coincides with the orthographic projection of the first reflective layer 11 on the first surface S1, or the orthographic projection of the opening H of the second reflective layer 12 on the first surface S1 falls within the orthographic projection of the first reflective layer 11 on the first surface S1.

[0092] The light emitting unit 14 is located on the side of the second reflective layer 12 away from the substrate 10. In specific implementation, the orthographic projection of the light emitting unit 14 on the first surface S1 covers the orthographic projection of the opening H on the first surface S1, thereby facilitating the increase of the incidence efficiency of the light emitted by the light emitting unit 14 into the substrate 10 through the opening H, and improving the utilization rate of the light. For example, the backlight unit can include a plurality of light emitting units 14, one light emitting unit 14 corresponding to one opening H, and the orthographic projection of the light emitting unit 14 on the first surface S1 covers the orthographic projection of the corresponding opening H on the first surface S1, which is not limited herein.

[0093] In specific implementation, the light emitting unit 14 can be a light emitting diode (LED), a mini light emitting diode (Mini LED), or a micro light emitting diode (Micro LED), etc. The main difference among the LED, the Mini LED, and the Micro LED lies in the size, wherein the planar size of the LED is usually greater than 200 μm, the planar size of the Mini LED is usually between 50 μm and 200 μm, and the planar size of the Micro LED is usually less than 50 μm. In addition, the light emitting unit can also be an organic light emitting diode (OLED) or other light emitting devices, which is not limited herein.

[0094] In the embodiments of the present disclosure, as shown in FIGS. 2A and 2B, the light L emitted by the light emitting unit 14 enters the first reflective layer 11 after entering the groove G, is reflected to the surrounding through the first reflective layer 11, part of the light is reflected to the second reflective layer 12 through the first reflective layer 11, and after being reflected by the second reflective layer 12, is directly emitted to the outside of the substrate 10 through the second surface S2 of the substrate 10, and part of the light is emitted to the outside of the substrate 10 through the second surface S2 after being reflected between the second reflective layer 12 and the second surface S2 multiple times. After the light emitted by the light emitting unit 14 is reflected multiple times through the first reflective layer 11 and the second reflective layer 12, it has a certain diffusion and uniform light effect, which can reduce the use of the diffusion film.

[0095] In the embodiments of the present disclosure, as shown in FIGS. 2A and 2B, the backlight unit further includes a filling structure 13. The filling structure 13 is located between the light emitting unit 14 and the first reflective layer 11. In some embodiments,

[0096] In some embodiments, the filling structure 13 can form a color conversion structure for performing color conversion on the light emitted by the light emitting unit 14 to convert the color of the light emitted by the light emitting unit 14 into a desired color. Specifically, the material of the filling structure 13 can include grass materials such as fluorescent materials or quantum dot materials that can perform color conversion, which are not limited herein. For example, the light emitting unit 14 is a blue light LED, and the filling structure 13 can convert the blue light emitted by the light emitting unit 14 into white light. In specific implementation, as shown in FIGS. 2A and 2B, the filling structure 13 can be filled in the groove G.

[0097] In some embodiments, the filling structure 13 can be a transparent material, for example, air or transparent optical glue, which is not limited herein. In specific implementation, as shown in FIGS. 2A and 2B, the filling structure 13 can be filled in the groove G. In some embodiments, as shown in FIGS. 11B and 11C, when the filling structure 13 adopts a transparent material such as transparent optical glue, a color conversion structure 20 can also be made on the side of the filling structure 13 away from the substrate 10 and between the filling structure 13 and the light emitting unit 14, which is not limited herein.

[0098] In the backlight unit provided in the embodiments of the present application, the light emitted by the light emitting unit 14 is directly color converted by the filling structure 13 or color converted by the color conversion structure arranged between the filling structure 13 and the light emitting unit 14, and compared with the backlight module in the related art shown in FIG. 1, the overall thickness is smaller, thereby further reducing the thickness of the backlight module and being beneficial to meeting the requirement of thinning of the display device.

[0099] FIG. 3 is a schematic diagram of a planar structure of a second reflective layer provided in the embodiments of the present disclosure.

[0100] In the embodiments of the present disclosure, as shown in FIGS. 2A and 2B, the second reflective layer 12 includes a first pattern layer 121 and a second pattern layer 122 arranged in layers.

[0101] The first pattern layer 121 includes a first hollow K1, and a normal projection of the first hollow K1 on the first surface S1 coincides with a normal projection of the opening K1 on the first surface S1, and the first hollow K1 is used to form part of the opening H.

[0102] It should be noted that the normal projection of the first hollow K1 on the first surface S1 coincides with the normal projection of the opening K1 on the first surface S1, which can be that the normal projection of the first hollow K1 on the first surface S1 completely coincides with the normal projection of the opening K1 on the first surface S1, or partially coincides.

[0103] For example, in some embodiments, the first hollow K1 is completely coincident with the opening K1 on the first surface S1. As shown in FIGS. 2A and 2B, the first hollow K1 and the opening K1 can be formed simultaneously after the first pattern layer 121 and the second pattern layer 122 are deposited, and the first pattern layer 121 and the second pattern layer 122 are etched to form the opening H, so that the first hollow K1 is completely coincident with the opening K1 on the first surface S1.

[0104] In some embodiments, the first pattern layer 121 and the second pattern layer 122 can be etched respectively to form the opening H. Depending on the specific process, the first hollow K1 can be completely coincident with the opening K1 on the first surface S1, or the first hollow K1 can fall within the opening K1 on the first surface S1, and the like, which are not limited herein.

[0105] The second pattern layer 122 includes a reinforcing pattern P. The reinforcing pattern P is arranged around the first hollow K1, and the reinforcing pattern P is at least partially within the projection of the corresponding groove G on the first surface S1. Specifically, as shown in FIGS. 2A and 2B, the reinforcing pattern P is arranged at least on the portion of the second reflective layer 12 that protrudes inwardly of the groove G, that is, the reinforcing pattern P is arranged at least on the portion where the roof structure is located. The reinforcing pattern P of the second pattern layer 122 is formed by etching the second pattern layer 122 to form a specific pattern, and the reinforcing pattern P specifically includes a hollow region formed by etching and a solid portion that is not etched. In the arrangement region of the reinforcing pattern P, the first pattern layer 121 is arranged as a continuous whole layer structure. For example, as shown in FIG. 3, the reinforcing pattern P of the second pattern layer 122 includes a solid portion 122A and a hollow region 122B between adjacent solid portions 122A, and the hollow region 122B exposes the solid of the first pattern layer 121. FIG. 3 can be regarded as a top view of FIG. 2A, or as a bottom view of FIG. 2B, and FIGS. 2A and 2B can be regarded as a sectional view of FIG. 3 along the sectional line A-A.

[0106] By setting the second reflective layer 12 as a two-layer structure including the first pattern layer 121 and the second pattern layer 122, especially in the part corresponding to the roof structure, the reinforcing pattern P etched by the second pattern layer 122 forms a reinforcing rib structure, which is advantageous to improve the strength of the roof structure compared with the roof structure including only the first pattern layer 121, avoiding the problem that the roof structure is excessively bent downward or curved upward due to excessive gravity and / or internal stress after the groove G is etched with the second reflective layer 12 as a mask. Moreover, in the setting area of the reinforcing pattern P, the second pattern layer 122 forms a hollow area 122B by etching, and the etched part is advantageous to reduce the overall weight of the roof structure, further improving the stability of the roof structure on the basis of taking into account the influence of the strength and weight of the roof structure.

[0107] FIG. 4A is a schematic diagram of a cross-sectional structure of a second reflective layer according to an embodiment of the present disclosure; and FIG. 4B is a schematic diagram of another cross-sectional structure of a second reflective layer according to an embodiment of the present disclosure.

[0108] In some embodiments, in combination with FIGS. 2A, 3 and 4A, where FIG. 4A can be regarded as a cross-sectional view of FIG. 3 along the cross-sectional line B-B, the second pattern layer 122 is located between the first pattern layer 121 and the substrate 10. The first pattern layer 121 covers the solid part 122A of the second pattern layer and covers the hollow area 122B between the solid parts 122A. Since the periphery of the solid part 122A is the hollow area 122B, the height of the position where the hollow area 122B is located is lower than the height of the position where the solid part 112A is located, and when the first pattern layer 121 is made on the side of the second pattern layer 122 away from the substrate 10 by a thin film deposition process such as sputtering deposition, the first pattern layer 121 forms a ramping part 1210 on the side surface of the solid part 122A, thereby connecting the part of the first pattern layer 121 located in the hollow area 122B and the part of the first pattern layer 121 located on the surface of the solid part 122A.

[0109] In some embodiments, as shown in FIG. 2B, FIG. 3 and FIG. 4B, which can be regarded as a sectional view of FIG. 3 along sectional line B-B, the second pattern layer 122 is located on the side of the first pattern layer 121 away from the substrate 10. In implementation, the second pattern layer 122 can be formed on the surface of the side of the first pattern layer 121 away from the substrate 10 by a thin film deposition process such as sputtering deposition, and then the second pattern layer 122 is etched to form the reinforcing pattern P by an etching process. Since the first pattern layer 121 is a continuous whole layer structure and the first pattern layer 121 forms a relatively flat surface by a thin film deposition process, forming the second pattern layer 122 on the first pattern layer 121 can avoid the formation of a climbing part of the second pattern layer 122 on the surface of the first pattern layer 121, and reduce the problem of stress concentration of the first pattern layer 121 or the second pattern layer 122 at the climbing position, thereby improving the uniformity of stress distribution of the roof structure and further improving the stability of the roof structure.

[0110] In some embodiments, as shown in FIG. 2A, FIG. 2B and FIG. 3, the orthographic projection of the reinforcing pattern P on the first surface S1 is a central symmetric figure, thereby improving the uniformity of stress distribution in the area where the reinforcing pattern P is located and further improving the stability of the roof structure.

[0111] In some embodiments, the symmetry center Po of the orthographic projection of the reinforcing pattern P on the first surface S1 coincides with the geometric center Go of the orthographic projection of the groove G on the first surface S1, thereby making the stress received by the reinforcing pattern P uniformly distributed around the geometric center Go of the orthographic projection of the groove G on the first surface S1 and further improving the stability of the roof structure. In implementation, the orthographic projection of the groove G on the first surface S1 can be a central symmetric figure such as a circle, or can be regarded as a central symmetric figure, and the geometric center Go of the orthographic projection of the groove G on the first surface S1 is the symmetry center of the orthographic projection of the groove G on the first surface S1. It should be noted that the symmetry center Po of the orthographic projection of the reinforcing pattern P on the first surface S1 coincides with the geometric center Go of the orthographic projection on the first surface S1, which is not limited to that the symmetry center Po of the orthographic projection of the reinforcing pattern P on the first surface S1 completely coincides with the geometric center Go of the orthographic projection on the first surface S1, but the symmetry center Po of the orthographic projection of the reinforcing pattern P on the first surface S1 falls within a certain size area centered on the geometric center Go of the orthographic projection of the groove G on the first surface S1, which is not limited herein.

[0112] In some embodiments, the orthographic projection of the reinforcing pattern P on the first surface S1 can also be a non-central symmetric figure, which is not limited herein.

[0113] In some embodiments, as shown in FIGS. 2A, 2B and 3, the part of the orthographic projection of the reinforcing pattern P on the first surface S1 falls within the orthographic projection of the groove G on the first surface S1, and the rest falls outside the orthographic projection of the groove G on the first surface S1.

[0114] For example, as shown in FIGS. 2A, 2B and 3, the orthographic projection of the reinforcing pattern P on the first surface S1 has an inner contour F3 and an outer contour F4, where the inner contour F3 specifically refers to the contour formed by the orthographic projection on the first surface S1 of the position where the solid part A of the reinforcing pattern P is closest to the opening H, the inner contour F3 falls within the orthographic projection of the groove G on the first surface, the outer contour F4 specifically refers to the contour formed by the orthographic projection on the first surface S1 of the position where the solid part A of the reinforcing pattern P is farthest from the opening H, the outer contour F4 falls outside the orthographic projection of the groove G on the first surface, and the first contour F1 formed by the orthographic projection of the groove G on the first surface S1 is located between the inner contour F3 and the outer contour F4, so that the part of the orthographic projection of the reinforcing pattern P on the first surface S1 that falls outside the orthographic projection of the groove G on the first surface S1 can be supported by the first surface S1 of the substrate 10, and the stress generated by the reinforcing pattern P can be transmitted to the substrate 10 for release, thereby further improving the stability of the eave structure. Specifically, as shown in FIGS. 5A, 8A, 9 and 10A, the reinforcing pattern P is only arranged in a local area, and two adjacent reinforcing patterns P are disconnected and spaced apart from each other, so that the orthographic projection of each reinforcing pattern P on the first surface can form a clear inner contour F3 and an outer contour F4.

[0115] It should be noted that in the embodiments shown in FIGS. 2A, 2B and 3, the inner contour F3 of the orthographic projection of the reinforcing pattern P on the first surface S1 coincides with the second contour F2 formed by the orthographic projection of the opening H on the first surface S1, but in specific implementation, the two may not coincide, for example, as shown in FIG. 8A, which is not limited herein.

[0116] In some embodiments, the distance W2 between the outer contour F4 and the first contour F1 is greater than or equal to 50 μm, and specifically can be 50 μm, 60 μm, 70 μm, etc. The greater the distance W2 between the outer contour F4 and the first contour F1, the better the effect of supporting and stress release of the reinforcing pattern P through the first surface S1 of the substrate 10, which can be set according to actual conditions in specific implementation, which is not limited herein.

[0117] In some embodiments, the distance W1 between the inner contour F3 and the first contour F1 is less than or equal to 50 μm, and the smaller the distance W1 between the inner contour F3 and the first contour F1, the smaller the width of the eave structure protruding to the inside of the groove G, and the more stable the eave structure. The distance W1 between the inner contour F3 and the first contour F1 can be set according to actual conditions in specific implementation, which is not limited herein.

[0118] In some embodiments, the first substrate layer is provided with a plurality of grooves, and the first pattern layer is provided with a plurality of first hollowed-out K1s corresponding to the grooves. One first hollowed-out K1 is provided with one reinforcing pattern P around the first hollowed-out K1.

[0119] FIG. 5A is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure; and FIG. 5B is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure.

[0120] In some embodiments, as shown in FIGS. 5A and 5B, the second pattern layer can only include the reinforcing patterns P, and specifically, the second pattern layer is only used to set the solid portions 122A of the reinforcing patterns P.

[0121] In some embodiments, as shown in FIG. 5A, the reinforcing patterns P corresponding to different first hollowed-out K1s are spaced apart at a certain distance and are disconnected from each other. For example, in the actual production, only the regions of the solid portions 122A of the reinforcing patterns P corresponding to the second pattern layer can be reserved in the etching process, and the portions of the second pattern layer corresponding to the hollowed-out regions and the portions between the two reinforcing patterns P are etched away, so that the solid portions 122A of the two reinforcing patterns P are disconnected from each other.

[0122] In some embodiments, as shown in FIG. 5B, the reinforcing patterns P corresponding to different first hollowed-out K1s are directly connected and form an integrated structure. For example, in the actual production, only the portions of the solid portions 122A of the reinforcing patterns P corresponding to the second pattern layer can be reserved in the etching process, and the portions of the second pattern layer corresponding to the hollowed-out regions are etched away, so that the solid portions 122A of the two reinforcing patterns P are directly connected, which is not limited herein.

[0123] FIG. 6 is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure.

[0124] In some embodiments, the second pattern layer can include the reinforcing patterns P and non-pattern portions NP. For example, as shown in FIG. 6, the different reinforcing patterns P are spaced apart at a certain distance, but the different reinforcing patterns P are connected through the non-pattern portions NP. For example, in the actual production, the solid portions 122A of the reinforcing patterns P are reserved in the etching process, and the non-pattern portions NP between the solid portions 122A are reserved, so that the solid portions 122A of the different reinforcing patterns P are connected through the non-pattern portions NP.

[0125] In some embodiments, the orthographic projection of the first pattern layer 121 on the first surface S1 covers the orthographic projection of the second pattern layer 122 on the first surface S1. For example, as shown in FIGS. 5A, 5B and 6, the first pattern layer 121 is provided with a continuous whole-layer structure in the regions other than the first hollowed-out K1s. This is not limited herein.

[0126] In some embodiments, the first pattern layer 121 and the second pattern layer 122 can be made of different materials. For example, the first pattern layer 121 and the second pattern layer 122 can be selected from materials with high reflectivity, such as molybdenum (Mo), aluminum (Al), silver (Ag), etc., to improve the reflection effect. When the first pattern layer 121 and the second pattern layer 122 are made of different materials, a clear boundary can be observed in the microscopic image at the boundary between the first pattern layer 121 and the second pattern layer 122. In a specific implementation, the first pattern layer 121 can be made of a material with strong corrosion resistance, such as molybdenum, and the second pattern layer 122 can be made of a material with weak corrosion resistance. The first pattern layer 121 is arranged on the side of the second pattern layer 122 away from the substrate 10, so that when the substrate 10 is etched using the second reflective layer 12 as a mask to form the groove G, the etching liquid (hydrogen fluoride, etc.) will not etch the second reflective layer 12, and the stability of the roof structure is improved. This is not limited.

[0127] In some embodiments, the first pattern layer 121 and the second pattern layer 122 can be made of the same material. The first pattern layer 121 and the second pattern layer 122 can be made of a material with high reflectivity and high corrosion resistance, such as molybdenum (Mo), silver (Ag), etc. When the first pattern layer 121 and the second pattern layer 122 are made of the same material, such as molybdenum, the first pattern layer 121 can be arranged on the side of the second pattern layer 122 away from the substrate 10, or the second pattern layer 122 can be arranged on the side of the first pattern layer 121 away from the substrate 10, which is not limited. Depending on the specific manufacturing process and the influence of the specific material properties used, when the first pattern layer 121 and the second pattern layer 122 are made of the same material, a clear boundary can be observed in the microscopic image at the boundary between the first pattern layer 121 and the second pattern layer 122, or it can be difficult to observe a clear boundary. For example, when the first pattern layer 121 is arranged on the side of the second pattern layer 122 away from the substrate 10, the first pattern layer 121 climbs on the side of the solid part 122A of the second pattern layer 122 in the area of the strengthening pattern P, and the climbing position can have a clear delamination phenomenon. This is not limited.

[0128] In some embodiments, the first pattern layer 121 and the second pattern layer 122 are made of the same material, and the thickness of the film layer close to the substrate 10 is greater than or equal to the thickness of the film layer away from the substrate 10 in both the first pattern layer 121 and the second pattern layer 122. For example, when the first pattern layer 121 is arranged on the side of the second pattern layer 122 away from the substrate 10, the thickness of the second pattern layer 122 can be arranged to be much greater than the thickness of the first pattern layer 121, so that when the first pattern layer 121 is etched to form the first hollow K1, the second pattern layer 122 has sufficient thickness to reduce the adverse effects of over-etching of the second pattern layer 122 by the etching liquid. For example, when the second pattern layer 122 is arranged on the side of the first pattern layer 121 away from the substrate 10, the thickness of the first pattern layer 121 can be arranged to be much greater than the thickness of the second pattern layer 122, so that when the second pattern layer 122 is etched to form the patterned area, the first pattern layer 121 has sufficient thickness to reduce the adverse effects of over-etching of the first pattern layer 121 by the etching liquid.

[0129] In some embodiments, the reinforcing pattern P includes a plurality of strip structures, and / or a plurality of ring structures. For example, the reinforcing pattern P includes only a plurality of strip structures, only a plurality of ring structures, or both a plurality of strip structures and a plurality of ring structures.

[0130] For example, as shown in FIG. 3, the reinforcing pattern P includes a plurality of mutually separate strip structures, i.e., the shape of the orthographic projection of the solid part 122A of the reinforcing pattern P on the first surface S1 is a plurality of strips, and the adjacent strip structures are separated from each other, and the interval between the two adjacent strip structures is the hollow area 122B.

[0131] As shown in FIG. 3, the strip structures extend in a direction away from the opening H, and the plurality of strip structures are arranged in a direction around the opening H, and the extension directions of all the strip structures of the same reinforcing pattern P intersect at a first point O, and the first point O is located within the opening H. Thus, a radial pattern is formed.

[0132] In specific implementation, the first point O and the geometric center Go of the groove G can be arranged on the same straight line perpendicular to the first surface S1, that is, the orthographic projection of the first point O on the first surface S1 coincides with the orthographic projection of the geometric center Go of the groove G on the first surface S1. This is not limited herein.

[0133] In some embodiments, the same reinforcing pattern P includes a number of strip structures greater than or equal to 8, so that the strip structures are evenly distributed along the periphery of the first hollow K1, and sufficient to ensure the strength of the roof structure. In specific implementation, the angle between adjacent two strip structures in the same reinforcing pattern P can be set to be the same. For example, when the same reinforcing pattern P includes 8 strip structures, the angle between adjacent two strip structures can be set to 45°. With the number of strip structures included in the same reinforcing pattern P changing, the angle between adjacent two strip structures can change accordingly, which is not limited herein. Considering the error of the manufacturing process, the angle between adjacent two strip structures in the same reinforcing pattern P can not be exactly the same, but can fluctuate within an error range, which is not limited herein.

[0134] In some embodiments, as shown in FIG. 3, the dimension B1 of the strip structure perpendicular to the extension direction of the strip structure is greater than or equal to 3 μm. The dimension B1 of the strip structure perpendicular to the extension direction of the strip structure needs to have a larger width, thereby improving the strength of the roof structure.

[0135] In some embodiments, as shown in FIG. 3, the maximum dimension B1 of the strip structure along the extension direction of the strip structure is not greater than wherein L represents the perimeter of the orthographic projection of the first hollow K1 on the first surface, n represents the number of strip structures included in the same reinforcing pattern, and C1 represents the spacing between the end portions of adjacent two strip structures on the side close to the first hollow. The value of C1 is greater than or equal to 10 μm.

[0136] Specifically, under the premise that the number of strip structures is determined, the larger the dimension of the strip structure perpendicular to the extension direction of the strip structure, the heavier the weight generated by the reinforcing pattern P, which can cause the roof structure to sag due to its own heavy weight. By limiting the dimension of the strip structure perpendicular to the extension direction of the strip structure, the weight of the roof structure is controlled, thereby further improving the stability of the roof structure under the premise of ensuring the strength of the roof structure. The dimension of the strip structure perpendicular to the extension direction of the strip structure is affected by the spacing C1 between the end portions of adjacent two strip structures. The larger the spacing C1 between the end portions of adjacent two strip structures, the smaller the dimension of the strip structure perpendicular to the extension direction of the strip structure. In specific implementation, the spacing C1 between the end portions of adjacent two strip structures can be set to be greater than or equal to 10 μm, thereby improving the stability of the roof structure under the premise of comprehensively considering the strength and weight of the roof structure.

[0137] FIG. 7A is a planar physical diagram of a second reflective layer for testing provided by an embodiment of the present disclosure; and FIG. 7A is a schematic diagram of a groove etching process provided by an embodiment of the present disclosure.

[0138] As shown in FIG. 7A, the second reflective layer with a strip structure reinforcing pattern is used as a mask to open grooves in the substrate to test the stability of the roof structure. The groove opening process is shown in FIG. 7B. In combination with FIG. 2B, FIG. 3 and FIG. 7A, the substrate 10 is provided with a plurality of grooves G, one groove G corresponds to one opening H, the first pattern layer 121 is provided with a first hollow K1 corresponding to the first opening H, and the second pattern layer 122 is provided with a reinforcing pattern P around the first hollow K1. The solid part 122A of the reinforcing pattern P is in a strip structure, and the area between the strip structures is a hollow area 122B. In the embodiment shown in FIG. 7A, the solid parts 122A of the reinforcing pattern P are connected together in the manner shown in FIG. 5B. In a plurality of tests, the size B1 of the strip structure along the direction perpendicular to its own extension direction, the number n of the strip structures provided around the first hollow K1, the caliber D of the opening H (which can be represented by the maximum size of the orthogonal projection of the opening H on the first surface S1), and the etching depth h of the groove G are changed respectively to test the stability of the roof structure 12 under different conditions. In the plurality of tests, the size B1 of the strip structure along the direction perpendicular to its own extension direction, the number n of the strip structures, the caliber D of the opening H and the etching depth h of each test are shown in Table 1 below:

[0139] Table 1 Test parameters of a plurality of tests

[0140] According to the results of the above plurality of tests, by using the second reflective layer structure shown in FIG. 7A as a mask, the probability of peeling (bending, falling off, etc.) of the roof structure during the etching process of the groove G is greatly reduced. Table 2 below records the probability of peeling of the roof structure corresponding to different etching depths h in the third test of Table 1. It can be seen that when the etching depth h is within 60 μm, the probability of peeling of the roof structure is less than 0.1%, which greatly improves the stability of the roof structure.

[0141] Table 2 Peeling rate of the roof structure

[0142] FIG. 8A is a schematic plan view of another second reflective layer according to an embodiment of the present disclosure.

[0143] In some embodiments, the reinforcing pattern P comprises a plurality of mutually separated ring structures, i.e., the shape of the orthographic projection of the solid part 122A of the reinforcing pattern P on the first surface S1 is a plurality of ring shapes, and the adjacent ring structures are mutually separated, and the spacing area between the adjacent ring structures is the hollow area 122B. Any two of the plurality of ring structures are coaxial and arranged at the same angle, and the orthographic projection of each on the first surface is a similar image. Any two of the ring structures are coaxial, specifically, the geometric centers of the two ring structures are located on the same straight line perpendicular to the first surface S1, and the similar image means that the shapes are approximately the same but the sizes are different. For example, as shown in FIG. 8A, the orthographic projection of the ring structure on the first surface S1 is a circular ring. Considering the strength and weight of the roof structure and other factors, the radial width B2 of the ring structure can be valued before 3 μm-100 μm, for example, can be 3 μm, 5 μm, 7 μm, 8 μm, 100 μm, etc., which is not limited here; the radial spacing C2 between the adjacent two ring structures can be valued between 10 μm-100 μm, for example, can be 10 μm, 15 μm, 20 μm, 100 μm, etc., which is not limited here.

[0144] FIG. 8B is a schematic diagram of possible shapes of the reinforcing pattern provided by the embodiments of the present disclosure.

[0145] In some embodiments, as shown in FIG. 8B, the orthographic projection of the ring structure on the first surface S1 can also be a polygon (such as a square, a rectangle, a rhombus, etc.), an ellipse or other special-shaped, which is not limited here. In specific implementation, the width of the ring structure along the direction perpendicular to the circumference of the ring structure itself, and the spacing between the adjacent two ring structures along the direction perpendicular to the circumference of the ring structure itself, can be set according to the way when the orthographic projection of the ring structure on the first surface S1 is a circular ring, which is not limited here.

[0146] FIG. 9 is a schematic diagram of another planar structure of the second reflecting layer provided by the embodiments of the present disclosure.

[0147] In some embodiments, in combination with FIGS. 3, 8A and 9, the reinforcing pattern P comprises a plurality of mutually separated strip structures and a plurality of mutually separated ring structures, and the strip structures and the ring structures intersect with each other to form a grid structure. Specifically, the strip structures extend away from the direction of the opening H, and are arranged around the opening H, and the extension directions of all the strip structures of the same reinforcing pattern P intersect at a first point O, and the first point O is located within the opening H, thereby forming a radial pattern. Any two of the plurality of ring structures are coaxial and arranged at the same angle, and the orthographic projection of each on the first surface is a similar image. In specific implementation, the geometric center of the first point O where the extension directions of all the strip structures intersect and the geometric center of the ring structure can be located on the same straight line perpendicular to the first surface S1, which is not limited here.

[0148] In implementation, the specific arrangement of the strip structure in the grid structure and the specific arrangement of the ring structure can be arranged according to the foregoing embodiments, which will not be repeated here.

[0149] FIG. 10A is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure; and FIG. 10B is a schematic diagram of a planar structure of another second reflective layer according to an embodiment of the present disclosure.

[0150] In some embodiments, as shown in FIGS. 10A and 10B, the reinforcing pattern P includes a plurality of second hollows K2. The plurality of second hollows K2 can be formed by etching the second pattern layer 122, and the second pattern layer 122 in the area outside the second hollows K2 can be reserved.

[0151] In implementation, as shown in FIGS. 10A and 10B, the plurality of second hollows K2 included in the reinforcing pattern P can be divided into a plurality of second hollow groups arranged in turn in a direction away from the opening H, and each second hollow group includes a plurality of second hollows K2 arranged in a direction around the opening H. As shown in FIGS. 10A and 10B, the plurality of second openings H2 in the same second hollow group are arranged on the same circle with the geometric center of the opening H as the center. The second hollows K2 formed in the second pattern layer 122 are the hollow areas 122B of the reinforcing pattern P, and the second pattern layer 122 outside the second hollows K2 is the solid part 122A of the reinforcing pattern P.

[0152] In some embodiments, as shown in FIGS. 10A and 10B, the maximum size B3 of the second hollow K2 can be between 3 μm and 100 μm. It should be noted that the maximum size of the second hollow K2 refers to the size of a single second hollow K2 in the direction of its largest aperture. Specifically, the shape of the second hollow K2 can be circular, elliptical, polygonal, etc., and when the shape of the second hollow K2 is circular, the maximum size is the diameter of the circle, when the shape of the second hollow K2 is elliptical, the maximum size is the length of the major axis of the ellipse, when the shape of the second hollow K2 is polygonal, the maximum size is the length of the longest diagonal of the polygon, and when the shape of the second hollow K2 is other shapes, the same applies, which will not be repeated here. In some embodiments, the maximum size B3 of all the second hollows K2 can be set to be the same. In some embodiments, the maximum size B3 of the second hollows K2 in the same second hollow group can be set to be the same, and the maximum size B3 of the second hollows K2 belonging to different second hollow groups can be different. In some embodiments, the maximum size B3 of the second hollow K2 can also be set in other ways, which will not be limited here.

[0153] In some embodiments, as shown in FIGS. 10A and 10B, the distance C3 between two adjacent second hollows K2 can be in the range of 10-100 μm. In some embodiments, the distance between two adjacent second hollows K2 in the same second hollow group can be in the range of 10-100 μm, which is not limited herein.

[0154] In some embodiments, as shown in FIG. 10A, the reinforcing pattern P is arranged only in a local area. The reinforcing patterns P are spaced apart from each other and disconnected, and the areas between the reinforcing patterns P expose the first surface of the first pattern layer 121. The shape of the outer contour F4 of the orthographic projection of the reinforcing pattern P on the first surface can be a regular shape such as a circle or a regular polygon, or an irregular shape, which is not limited herein.

[0155] In some embodiments, as shown in FIG. 10B, the second pattern layer can include reinforcing patterns P and non-patterned portions NP. The reinforcing patterns P are spaced apart from each other, but connected by the non-patterned portions NP. The first pattern layer 121 between two adjacent reinforcing patterns P is covered by the reinforcing patterns P.

[0156] FIG. 11A is a schematic view of a cross-sectional structure of another backlight unit according to an embodiment of the present disclosure; FIG. 11B is a schematic view of a cross-sectional structure of another backlight unit according to an embodiment of the present disclosure; and FIG. 11C is a schematic view of a cross-sectional structure of another backlight unit according to an embodiment of the present disclosure.

[0157] In some embodiments, as shown in FIGS. 11A, 11B and 11C, the backlight unit further includes a light diffusion structure 15. The light diffusion structure 15 is located between the substrate 10 and the second reflective layer 12, and is used to diffuse the light incident on the light diffusion structure 15, so as to diffuse the incident light of a single angle into light of multiple angles for emission, thereby improving the uniformity of the backlight light.

[0158] In some embodiments, as shown in FIGS. 11A and 11B, the light diffusion structure 15 can be a plurality of protruding structures, and the light diffusion structure 15 can be formed by making a layer of resin material on the surface of the substrate and then performing a patterning process on the resin material to form protruding structures with light diffusion effect, which is not limited herein. In specific implementation, as shown in FIGS. 11A and 11B, the minimum distance W3 between the edge of the light diffusion structure 15 and the edge of the groove G can be set to 5-15 μm, for example, 10 μm, to reserve a process margin for the etching process. In specific implementation, the smaller the minimum distance W3 between the edge of the light diffusion structure 15 and the edge of the groove G under the requirement of etching process precision, the larger the area where the light diffusion structure 15 can be arranged, and thus the better the light diffusion effect. The size of the minimum distance W3 between the edge of the light diffusion structure 15 and the edge of the groove G can be adjusted according to actual conditions, which is not limited herein. Since the light diffusion structure 15 is directly formed on the surface of the substrate 10 by the coating and etching processes, compared with the structure using the diffusion film 3 in the related art shown in FIG. 1, the optical adhesive film and other films used in the assembly process of the diffusion film 3 can be reduced, and the space occupied by the light diffusion structure 15 can be reduced to the greatest extent, thereby facilitating the reduction of the overall thickness of the light diffusion structure.

[0159] In some embodiments, as shown in FIG. 11C, the light diffusion structure 15 can also be a light diffusion layer including a plurality of etched pits. Specifically, the light diffusion structure 15 can be formed by making a layer of resin material on the surface of the substrate and then performing an etching process on the resin material to form a plurality of pits with light diffusion effect on the surface of the resin material layer away from the substrate, which is not limited herein. In specific implementation, as shown in FIG. 11C, the minimum distance W3 between the edge of the pit and the edge of the groove G can be set to 5-15 μm, for example, 10 μm, to reserve a process margin for the etching process.

[0160] In some embodiments, as shown in FIG. 11A, FIG. 11B and FIG. 11C, the backlight unit can further include a third reflective layer 16. The third reflective layer 16 is located on the side of the light diffusion structure 15 facing away from the substrate 10. The third reflective layer 16 covers the light diffusion structure 15. The third reflective layer 16 is provided with openings for transmitting the light emitted by the light emitting unit into the groove. In implementation, the projection of the groove G on the first surface can fall within the projection of the opening of the third reflective layer 16 on the first surface, which is not limited herein. The third reflective layer 16 is mainly used for reflecting the light transmitted by the light diffusion structure 15. The third reflective layer 16 can be made of a material with high reflectivity, thereby improving the utilization rate of light. Since the third reflective layer 16 is not directly used as a mask for etching the groove G in general cases, and the third reflective layer 16 is not used to form the eave structure, the material of the third reflective layer 16 can be selected from a wider range compared with the material of the second reflective layer 12. In implementation, the reflectivity of the material of the third reflective layer 16 can be greater than the reflectivity of the material of the second reflective layer 12, which is not limited herein.

[0161] In some embodiments, as shown in FIG. 11B and FIG. 11C, the material of the filling structure 13 can be transparent optical glue, and the backlight unit further includes a color conversion structure 20. The color conversion structure 20 is located between the filling structure 13 and the light emitting unit 14, thereby converting the color of the light emitted by the light emitting unit. In implementation, the color conversion structure 20 can be filled at least in the opening H of the second reflective layer 12, thereby ensuring sufficient conversion of the color of the light. The color conversion structure 20 can also be arranged in other areas as long as it can convert the color of the light incident into the groove G, which is not limited herein.

[0162] In some embodiments, as shown in FIG. 11B and FIG. 11C, the backlight unit further includes an isolation dam 21 arranged around the opening H of the second reflective layer 12. The isolation dam 21 can define the arrangement area of the color conversion structure 20, and can be used to reflect the light emitted by the color conversion structure 20 to the periphery of the opening H, thereby improving the utilization rate of light.

[0163] In some embodiments, as shown in FIG. 11A, FIG. 11B and FIG. 11C, the backlight unit further includes a first encapsulation layer 17. The first encapsulation layer 17 is located between the second reflective layer 12 and the light emitting unit 14, and the first encapsulation layer 17 covers the second reflective layer 12 and the opening H. The first encapsulation layer 17 can protect the second reflective layer 12, the filling structure 13 and other film layers, thereby reducing the risk of failure of the filling structure 13 and other film layers caused by water and oxygen corrosion. In implementation, the first encapsulation layer 17 can be a single-layer structure or a multi-layer structure, which is not limited herein.

[0164] In some embodiments, as shown in FIGS. 11A, 11B and 11C, the backlight unit further comprises a driving circuit layer. The driving circuit layer is formed between the first encapsulation layer 17 and the light emitting unit 14. A driving circuit is formed in the driving circuit layer for driving the light emitting unit 14 to emit light. The driving circuit layer comprises the pad 18, and the light emitting unit 14 is electrically connected to the circuit in the driving circuit layer through the pad.

[0165] In some embodiments, as shown in FIGS. 11A, 11B and 11C, the backlight unit further comprises a second encapsulation layer 19. The second encapsulation layer 19 is located on the side of the light emitting unit 14 away from the substrate 10. The second encapsulation layer 19 is provided on the whole surface, thereby protecting the light emitting unit 14 and other film layers. In practice, the second encapsulation layer 19 can be made of white oil, white glue or other materials with high reflectivity, thereby reflecting the light to the opening H to improve the utilization of light. This is not limited herein.

[0166] The backlight unit provided by the embodiments of the present disclosure can further comprise other structures that must be provided to achieve specific functions, which can be made according to actual conditions in practice, and this is not limited herein. The structures of the above-mentioned embodiments of the present disclosure can be combined in the case of not conflicting with each other, and the structure formed after the combination is not described herein.

[0167] FIG. 12 is a schematic view of a cross-sectional structure of a display device provided by an embodiment of the present disclosure.

[0168] In a second aspect, the present disclosure provides a display device. As shown in FIG. 12, the display device comprises a display panel 200 and the backlight unit 100 provided by any of the above-mentioned embodiments. The display panel 200 can be a passive light emitting display panel, and the display panel 200 is located on the side of the substrate 10 of the backlight unit 100 away from the light emitting unit 14. The display device provided by the embodiments of the present disclosure has the same or similar technical effects as the backlight unit 100 provided by any of the above-mentioned embodiments in practice, and this is not described herein.

[0169] FIG. 13 is a schematic view of a cross-sectional structure of another display device provided by an embodiment of the present disclosure.

[0170] In some embodiments, as shown in FIG. 13, the display panel 200 can be a liquid crystal display panel. The display panel 200 comprises an array substrate 201 and a counter substrate 202 arranged oppositely, and a liquid crystal layer 203 located between the array substrate 201 and the counter substrate 202. In practice, as shown in FIG. 13, the substrate 10 of the backlight unit 100 can be reused as the substrate of the array substrate 201, that is, the film layer structure of the array substrate 201 can be directly made on the surface of the substrate 10 of the backlight unit 100, thereby being conducive to further reducing the thickness of the display device. This is not limited herein.

[0171] FIG. 14 is a flowchart of a method for manufacturing a backlight unit according to an embodiment of the present disclosure.

[0172] In a third aspect, the present disclosure provides a method for manufacturing a backlight unit. As shown in FIG. 14, the method for manufacturing the backlight unit includes the following steps:

[0173] S141: manufacturing a mask layer on a first surface of a substrate; the mask layer is provided with an etching opening for exposing the substrate; the mask layer includes a first pattern layer and a second pattern layer which are arranged in a stack; the second pattern layer includes a reinforcing pattern; the reinforcing pattern is arranged around the etching opening;

[0174] S142: etching the substrate through the etching opening to form a groove, and forming a second reflective layer corresponding to the mask layer and an opening of the second reflective layer corresponding to the etching opening; a normal projection of the opening on the first surface falls within a normal projection of the groove on the first surface;

[0175] S143: depositing a first reflective layer in the groove by using the second reflective layer as a mask;

[0176] S144: mounting a light-emitting unit; the light-emitting unit is arranged on a side of the second reflective layer away from the substrate.

[0177] The method for manufacturing the backlight unit according to the present disclosure is conducive to reducing the thickness of the backlight unit, and thus the thickness of the display device. In the method for manufacturing the backlight unit according to the present disclosure, the mask layer for forming the second reflective layer is used as a mask to etch the substrate to form the groove. In order to avoid the problem of peeling of the eave structure of the second reflective layer formed above the groove, the second reflective layer is manufactured as a two-layer structure including the first pattern layer and the second pattern layer in the method for manufacturing the backlight unit according to the present disclosure. The second pattern layer is provided with the reinforcing pattern in the part corresponding to the eave structure. The reinforcing pattern can reinforce the strength of the eave structure, and avoid the collapse of the eave structure due to the excessive weight of the eave structure, thereby improving the stability of the eave structure.

[0178] FIG. 15A is a schematic diagram of a manufacturing process of a backlight unit according to an embodiment of the present disclosure; and FIG. 15B is a schematic diagram of a planar structure of a mask layer according to an embodiment of the present disclosure.

[0179] For example, as shown in FIG. 15A, the method for manufacturing the backlight unit according to the present disclosure includes the following processes in the implementation:

[0180] 1. Form a mask layer 1200 on the first surface S1 of the substrate 10; the mask layer 1200 is provided with an etching opening H11 exposing the substrate 10; in some embodiments, as shown in FIG. 15B, the orthogonal projection of the etching opening H11 on the substrate 10 can be a circular ring, and a part of the mask layer 1200 in the center region of the circular ring is reserved as an etching auxiliary structure F to facilitate the formation of a protruding structure at the bottom of the groove G in the subsequent etching process; in some embodiments, the orthogonal projection of the etching opening H11 on the substrate 10 can also be a solid circle or other shapes, which are not limited herein; the orthogonal projection of the etching opening H11 on the substrate 10 is circular in this embodiment; the mask layer 1200 comprises a first pattern layer 121 and a second pattern layer 122 arranged in a stack; the second pattern layer 122 comprises a reinforcing pattern P; the reinforcing pattern P is arranged around the etching opening H11; wherein the first pattern layer 121 can be formed on the side of the second pattern layer 122 away from the substrate 10, or the second pattern layer 122 can be formed on the side of the first pattern layer 121 away from the substrate 10, which are not limited herein;

[0181] 2. Etching the substrate 10 exposed by the etching opening H11 through the etching opening H11; in the implementation, the substrate 10 can be etched by an etching liquid; since the etching liquid etches the substrate in all directions, for example, the etching liquid etches the substrate in a certain region directly below the mask layer 1200, thereby forming a groove G; after the groove G is etched, since the substrate 10 with a partial thickness below the etching auxiliary structure F is etched away, the etching auxiliary structure F loses support and is removed, and the etching opening H11 forms an opening H corresponding to the second reflective layer 12, and the mask layer 1200 forms the second reflective layer 12; at the same time, since the substrate 10 with a partial thickness below the second reflective layer 12 is etched to form the groove G, the orthogonal projection of the opening H on the first surface falls within the orthogonal projection of the groove G on the substrate 10, and the second reflective layer 12 between the edge of the opening H and the edge of the groove G protrudes towards the inside of the groove G relative to the substrate 10, forming a roof structure; wherein the reinforcing pattern P is at least partially arranged in the region corresponding to the roof structure; for example, the region corresponding to the roof structure completely coincides with the arrangement region of the reinforcing pattern P, or the arrangement region of the reinforcing pattern P is larger than the region corresponding to the roof structure, which are not limited herein;

[0182] 3. Depositing the first reflective layer 11 in the groove G by using the second reflective layer 12 as a mask; the first reflective layer 11 covers part of the inner wall of the groove G;

[0183] 4. Filling structure is made; in some embodiments, as shown in FIG. 15A, the filling structure 13 is filled in the groove G made in the foregoing process; in some embodiments, the filling structure 13 can adopt color conversion materials such as fluorescent powder, quantum dots, etc.; in some embodiments, the filling structure 13 can be air or inert gas; in some embodiments, the filling structure 13 can be transparent optical glue; when the filling structure 13 adopts transparent optical glue, after the filling structure 13 is filled in the groove G, a color conversion structure can also be made on the side of the filling structure 13 away from the substrate 10, as shown in FIG. 11B or FIG. 11C, which can be arranged at least in the opening H of the second reflective layer 12, without limitation here;

[0184] 5. The light emitting unit 14 is installed on the side of the second reflective layer 12 away from the substrate 10; wherein the filling structure 13 is located between the light emitting unit 14 and the first reflective layer 11; in specific implementation, the orthographic projection of the light emitting unit 14 on the first surface can be arranged to cover the orthographic projection of the opening H on the first surface, so as to improve the light utilization rate, without limitation here.

[0185] FIG. 16 is a schematic diagram of another manufacturing process of a backlight unit provided by an embodiment of the present disclosure.

[0186] In some embodiments, as shown in FIG. 16, a mask layer 1200 is made on the first surface S1 of the substrate 10, specifically including:

[0187] 1. A first pattern layer 121 is made on the first surface S1 of the substrate 10; specifically, the first pattern layer 121 can be formed by depositing a material for forming the first pattern layer 121 on the first surface S1 through sputtering deposition or the like, and then etching the material layer for forming the first pattern layer 121 through an etching process to form a part of the etching opening H11 located in the first pattern layer 121.

[0188] 2. A second pattern layer 122 is made on the side of the first pattern layer 121 away from the substrate 10; specifically, the second pattern layer 122 can be formed by depositing a material for forming the second pattern layer 122 on the first pattern layer 121 through sputtering deposition or the like, and then etching the material layer for forming the second pattern layer 122 through an etching process to form a part of the etching opening H11 located in the second pattern layer 122, and form the reinforcing pattern P in the second pattern layer 122.

[0189] In specific implementation, the manufacturing method of the backlight unit provided by the embodiment of the present disclosure can also be adjusted according to the specific structure of the backlight unit provided by the first aspect of the present disclosure, which will not be repeated here.

[0190] Although preferred embodiments of this disclosure have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this disclosure.

[0191] Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include such modifications and variations.

Claims

1. A backlight unit, wherein, The backlight unit comprises: a substrate; a first surface of the substrate is provided with a groove; a first reflective layer covers part of the inner wall of the groove; a second reflective layer covers the first surface; the second reflective layer comprises an opening, a projection of the opening on the first surface is located within a projection of the corresponding groove on the first surface, and the second reflective layer does not contact the inner wall of the groove; a light emitting unit is located on a side of the second reflective layer away from the substrate; 2. The backlight unit of claim 1, wherein, wherein the second reflective layer comprises a first pattern layer and a second pattern layer arranged in a stack; the first pattern layer comprises a first hollow, a projection of the first hollow on the first surface coincides with a projection of the opening on the first surface; the second pattern layer comprises a reinforcing pattern; the reinforcing pattern is arranged around the first hollow, and a projection of the reinforcing pattern on the first surface at least partially falls within a projection of the corresponding groove on the first surface.

3. The backlight unit of claim 1 or 2, wherein, The second pattern layer is located on a side of the first pattern layer away from the substrate.

4. The backlight unit of claim 3, wherein, The projection of the reinforcing pattern on the first surface is a central symmetric figure.

5. The backlight unit according to any one of claims 1 to 4, wherein, The center of symmetry of the projection of the reinforcing pattern on the first surface coincides with the geometric center of the projection of the groove on the first surface.

6. The backlight unit of claim 5, wherein, The reinforcing pattern comprises a plurality of strip structures and / or a plurality of ring structures.

7. The backlight unit of claim 6, wherein, The extension directions of all strip structures of the same reinforcing pattern intersect at a first point; the first point is located within the opening.

8. A backlight unit as defined in any one of claims 5-7, wherein The first point and the geometric center of the groove are located on the same straight line perpendicular to the first surface. The number of strip structures included in the reinforcing pattern is greater than or equal to 8.

9. The backlight unit of any one of claims 5-8, wherein: The strip-shaped structure has a dimension B1 perpendicular to the direction of its own extension, which is not greater than the strip structure has a dimension perpendicular to its own extension direction greater than or equal to 3 μm; 10. The backlight unit of claim 5, wherein, wherein L represents the circumference of the projection of the first hollow on the first surface, n represents the number of strip structures included in the same reinforcing pattern, C1 represents the spacing between the end portions of adjacent two strip structures on the side close to the first hollow, and C1 is greater than or equal to 10 μm.

11. The backlight unit of claim 10, wherein, Any two ring structures of the plurality of ring structures are coaxial and arranged at the same angle, and their respective projections on the first surface are similar figures. The projection of the ring structure on the first surface is a circular ring; the radial width of the ring structure is between 3 μm and 100 μm; 12. A backlight unit as defined in any one of claims 5-11, wherein, the spacing between adjacent two ring structures in the radial direction is between 10 μm and 100 μm.

13. The backlight unit of any one of claims 1-4, wherein, The strip structure and the ring structure intersect with each other to form a grid structure.

14. The backlight unit of claim 13, wherein, The reinforcing pattern comprises a plurality of second hollows. The maximum dimension of the second hollow is between 3 μm and 100 μm; 15. The backlight unit according to any one of claims 1 to 14, wherein, the spacing between adjacent two second hollows is between 10 μm and 100 μm. The projection of the groove on the first surface has a first contour, the projection of the reinforcing pattern on the first surface has an inner contour and an outer contour, and the first contour is located between the inner contour and the outer contour; The distance between the outer contour and the first contour is greater than or equal to 50 μm; The distance between the inner contour and the first contour is less than or equal to 60 μm.

16. The backlight unit of any of claims 1-15, wherein, The reinforcing patterns corresponding to different first hollows are directly connected to form an integrated structure.

17. The backlight unit of any of claims 1-16, wherein, The second pattern layer and the first pattern layer are made of the same material; In the two film layers of the second pattern layer and the first pattern layer, the thickness of the film layer close to the substrate side is greater than or equal to the thickness of the film layer away from the substrate side.

18. The backlight unit of any of claims 1-17, wherein, The orthographic projection of the first pattern layer on the substrate covers the orthographic projection of the second pattern layer on the substrate. The first pattern layer is a continuous whole layer structure in the area other than the first hollow.

19. The backlight unit according to any one of claims 1 to 18, further comprising a protruding structure in the recess, the protruding structure being lower than the first surface or flush with the first surface; and the first reflective layer covering the surface of the protruding structure.

20. A display device comprising: A display panel comprising the backlight unit according to any one of claims 1 to 19, and the display panel being located on the side of the substrate of the backlight unit away from the light emitting unit.

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